All living organisms are aged as they grow older. Also, the skin undergoes an aging process. Efforts to delay this aging process have been continuously made, and thus the nature and causes of aging have been continuously studied. Skin aging can be broadly divided into two types: intrinsic aging and extrinsic aging. Intrinsic aging is the progressive deterioration in physical structure and biological function that occurs with advancing age. Extrinsic aging is caused by external factors such as sunlight. Both intrinsic aging and extrinsic aging result in structural changes in the skin, and consequently, the skin becomes dry, losses elasticity and develops wrinkles.
More specifically, the structural changes of the skin resulting from aging, the epidermal, dermal and subcutaneous tissues of the skin become thin. Also, the components of the extracellular matrix (ECM) that is attributable for the firmness and tightness of the skin change. The extracellular matrix is a three-dimensional structure which contains inorganic salts, nutrients, aqueous solutions such as waste materials, and large polysaccharide molecules. It forms a network in the space surrounding cells to maintain the shape of tissue and plays an important role in signaling between cells and regulating the growth and differentiation of cells.
ECM components that have been mimicked till now are mostly of animal origin. However, components of animal origin are generally used in cosmetic products, because they pose safety problems, such as infection with pathogens.
Collagen accounting for 70-80% of the extracellular matrix is a long fiber-like protein that increases the strength and elasticity of the skin. It is known to have a close connection with skin aging, that is, a reduction in elasticity or the formation of wrinkles. However, collagens which are currently used are mostly of animal origin and are polymers having a molecular weight of about 300,000 Da, and thus the absorption of these collagens themselves into the skin is limited.
Hyaluronic acid, an ECM component, serves to combine skin dermal cells with each other and to delivery nutrients and allows the skin to retain a suitable amount of water. However, because hyaluronic acid is a polymer which has a molecular weight ranging from several hundred thousands to several millions and is highly viscous, the application thereof in cosmetic products is limited and it is difficult to permeate through the skin when it is applied directly to the skin.